La Unión Europea: mercado y competencia

Sin resume

Distance-based kernels for real-valued data

We consider distance-based similarity measures for real-valued vectors of interest in kernel-based machine learning algorithms. In particular, a truncated Euclidean similarity measure and a self-normalized similarity measure related to the Canberra distance. It is proved that they are positive semi-definite (p.s.d.), thus facilitating their use in kernel-based methods, like the Support Vector Machine, a very popular machine learning tool. These kernels may be better suited than standard kernels (like the RBF) in certain situations, that are described in the paper. Some rather general results concerning positivity properties are presented in detail as well as some interesting ways of proving the p.s.d. property.Peer ReviewedPostprint (author's final draft

Centaurea sulphurea Willd. (Asteraceae), a novelty for the Western Andalusian flora

Centaurea sulphurea Willd. (Asteraceae), a novelty for the Western Andalusian flora Palabras clave. Centaurea, Asteraceae, corología, Cádiz, Andalucía Occidental, Península Ibérica.Key words: Centaurea, Asteraceae, chorology, Cadiz, Western Andalusia, Iberian Peninsula

A new approach to influence analysis in linear models

propose a new approach to the study of influence in the General Linear Model based on conditional bias. This approach enables us to apply such an analysis to all particular cases of this model. The theoretical foundation, on which this approach is based, does not presuppose a particular hypothesis on the distribution of the variables. Applying the results obtained to the Multiple Linear Regression Model, measures of influence are obtained as already proposed by other authors. Finally we carry out an application of the results on the analysis of covariance

Influence analysis on discriminant coordinates

Discriminant analysis (DA), particularly Discriminant Coordinates (DC), is broadly applied in the scientific literature and included in many statistical software packages. DC is used to analyze biomedical data, especially for differential diagnosis on the basis of laboratory profiles. Papers handling influence analysis in DA can be found in the literature; however this topic has been scarcely touched upon in DC. In this paper the case-deletion approach is followed to introduce a perturbation in the data and influence measures are proposed to assess the effect on three statistics of interest: the transformation matrix, canonical directions and configuration of the sample centroids.Ministerio de Ciencia y Tecnologí

Static Analysis of Usefulness States in Transition P systems

Transition P Systems are a parallel and distributed computational model based on the notion of the cellular membrane structure. Each membrane determines a region that encloses a multiset of objects and evolution rules. Transition P Systems evolve through transitions between two consecutive configurations that are determined by the membrane structure and multisets present inside membranes. Moreover, transitions between two consecutive configurations are provided by an exhaustive non-deterministic and parallel application of evolution rules. But, to establish the rules to be applied, it is required the previous calculation of useful, applicable and active rules. Hence, computation of useful evolution rules is critical for the whole evolution process efficiency, because it is performed in parallel inside each membrane in every evolution step. This work defines usefulness states through an exhaustive analysis of the P system for every membrane and for every possible configuration of the membrane structure during the computation. Moreover, this analysis can be done in a static way; therefore membranes only have to check their usefulness states to obtain their set of useful rules during execution

Análisis de sensibilidad en el muestreo en poblaciones finitas

Las conclusiones de un análisis estadístico dependen en gran medida de las hipótesis de partida, en general expresadas en términos de un modelo, y de las observaciones experimentales. Esta dependencia motiva la necesidad de estudiar estimadores, tests ... que sean robustos ante determinadas perturbaciones del modelo, de identificar las observaciones atípicas o amortiguar el efecto de su presencia, y de evaluar el impacto de cada una de las opservaciones sobre las conclusiones del estudio. Naturalmente, la reflexión anterior es válida en el muestreo en poblaciones finitas. El estudio de las referencias a los problemas antes señalados, en el contexto del muestreo en poblaciones finitas, pone de manifiesto un desarrollo desigual de los distintos tópicos, y la importancia del esquema probabilístico desde el que se aborda la inferencia: población fija o modelo de superpoblación. En este trabajo se presentan algunas de las referencias sobre los problemas descritos. En particular, se recogen algunos resultados referentes a la robustez del estimador de razón y una recopilación exhaustiva de los diagnósticos de influencia en el muestreo en poblaciones finitas

El día de Santa Marina : tradición de la reconquista de Béjar

Copia digital. Valladolid : Junta de Castilla y León. Consejería de Cultura y Turismo, 2009-201

Criterios de evaluación para la enseñanza de la geografía, la historia y las ciencias sociales, según el modelo de principios científico-didácticos (P.C.D.)

En este artículo los autores nos presentan nuevos criterios de evaluación para la enseñanza de la Geografía, la Historia y las Ciencias Sociales; con el fin de que el alumnado adquiera una formación más integral y completa en la que tienen cabida la dimensión práctica, epistemológica y ético-filosófica. Para ello separan los conceptos de los hechos, porque poseen naturalezas distintas, y añaden los contenidos de carácter reflexivo, que serían los equivalentes a las correlaciones internas de los demás tipos de contenidos de cada tema. El resultado son cinco tipos de criterios: factuales, conceptuales, procedimentales, reflexivos y actitudinales. El fundamento de estos, es el modelo de los Principios Científico-Didácticos, elaborado por los autores en investigaciones anteriores, como forma innovadora y alternativa de aprendizaje.In this article the authors present new evaluation criteria for teaching Geography, History and Social Sciences in order to provide students with a more comprehensive and complete which has dimensions for the practical, epistemological and ethical-philosophical. For this, the authors have separated the concepts of facts, because they have different natures, and add the contents of thoughtfulness, which would be the equivalent to the internal correlations of the other types of contents of each issue. The results are five types of criteria: factual, conceptual, procedural, and attitudinal reflective. The basis of this, is the model of Scientific-Didactic Principles, developed by the authors in several previous research, as an innovative and alternative form